I’m in this forum because I plan to get a Silverado ZR2 but right now I have a 2016 Colorado diesel (which I 98% love and it’s why I kept it so long). But from the way you describe the noise it sounds like a problem I have on my truck (and other Colorados). I took it to a dealer for the service bulletin below but they kind of jerked me around - wanted $900 to replace the bump stops on the leaf springs - which I know is not the problem. But they wanted to start there. There is a clip in the axle housing cover that I feel is certain the cause of the noise. If I were you I’d find a way to get this clip replaced - I don’t think it’s very hard but I don’t enjoy working on such things now that I’m older.
My truck has been doing it for years. I only hear it when backing out of the drive or hitting certain kinds of bumps - and I’ve just learned to live with it. It doesn’t get worse with time.
